embedded based

8/4/2019 Embedded Based

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EMBEDDED BASED ANTI-COLLISION

SYSTEM IN TRAINS AND CONTROLLING OFUNMANNED RAIL GATES


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ABSTRACT

IR transmitter and RF receiver are placed in trains . IR receivers are placed in the tracks at a certain distance

apart while, the RF transmitter is placed near the gate.

IR signal is received when the IR transmitter comes in

line with the receiver. This is applicable when a singletrain or two trains are moving along the same track.

The microcontroller sends suitable control signals to thegate and also to the RF receiver in train via the RFtransmitter connected with it.

Thus, incase of trains moving along the same trackin opposite directions, suitable signals are send so thatcollision is prevented and also automated gate closure isachieved.


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AIM

To prevent the head - on collisions in trains and control the

unmanned rail gates automatically using embedded platform.


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INTRODUCTION

Automation at railways would provide a safe and secure

journey to the passengers.

At present ,GPS based system used to avoid rail accidentsonly available, mainly identifies the location of the trains.

Billions of rupees are spent at making railway operations free

of accidents, be it collision of trains or unmanned rail gates.

The usage of IR and RF signals helps in reducing the overallcost and betterment in design.

4


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TransceiverGPS Receiver

TransceiverMCUGPS Receiver

ExternalComputer

.

MCU

TRANSMITTER MODULE

RECEIVER MODULE

GPS-BASED SYSTEM


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DISADVANTAGES

Unclear resolution, which is difficult to find whether the

train is coming in the opposite track.

Hardware is larger in size and very expensive.

It requires computer as an external device to transfer the

information.


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IR

RECEIVER.2

(TSOP1738)

IR

RECEIVER.1

(TSOP1738)

MICROCONTROLLER

(AT89S52)ENCODER RF TRANSMITTER

DC MOTOR

AND

BUZZER

To the gate section.

Signal from

IR TXR(Train 1)

Signal from

IR Txn.2(Train 2)

OVERALL-LAYOUT

RF RECEIVER

MICROCONTROLLER

(AT89S52)

DECODER

DC MOTOR

AND

RELAY

Wired communication.

Wireless communication.

To

RF receiver

in train


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HARDWARE USED IR Transmitter(Would be placed in train)

TSOP 1738 Receivers RF 433.92 MHz transmitter and receiver pair

Microcontrollers (AT89s52)

Decoder

Encoder

Buzzer

DC Motor

Stepper motor

Relays

ULN 2003 IC

LM 7805 IC 555 Timer IC

Step down transformer(15-0-15) v

SOFTWARE USED

Embedded C using Keil


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ADVANTAGES

The proposed model is a cost effective one when compared

with the existing.

Advanced micro-controller AT89S52 with 8K bytes of In-

system re-programmable flash memory.

In TSOP1738, continuous data transmission is possible (up to2400 bytes).

Fine resolution and low power consumption.

On the whole, it provides a better way of preventing rail

accidents.


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PROCESSING OF CONTROLLER IN TRANSIMITTER SECTION

START

CHECKOUT

THE INPUTS

If

IR RX.1=

IR RX,2

==1

SIGNALS TRANSMITTED

FROM RF TRANSMITTER

TO RF RECEIVER.

If

IR RX.1^I

IR RX.2=1

CLOSURE OF GATE.

STOP

GATE REMAINS

OPEN.

TRAINS HALT

YES

NO

NO

YES


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PROCESSING OF CONTROLLER IN RECEIVER SECTION

start

Check for the input from

the RF receiver

While

(RX==X)

Relay trips

Enable buzzer

Stop

YES

Trains' continue

to move

NO


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MICROCONTROLLER

The AT89S52 low power, high performance CMOS 8-bit controller

is used in both the transmitter and receiver section in our project.

FEATURES:

8K Bytes of In-System Programmable (ISP) Flash Memory

256 x 8-bit Internal RAM

32 Programmable I/O LinesEight Interrupt Sources

4.0V to 5.5V Operating Range


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IRTRANSMITTERThe transmitter circuit consists of the following components:

IC 555

Resistors

Capacitors IR LED

The IR LED emitting infrared light is put on in the transmitting unit.To generate IR signal, 555 IC based astable multi-vibrator is used.

IC 555 is used to construct an astable multi-vibrator which hastwo quasi-stable states. It generates a square wave of frequency38.5kHz and amplitude 5Volts. It is required to switch ON the IRLED.


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DISCHARGE

vcc RESET

THRESHOLD

TRIGGER

GND CONTROL

RA

RB

C

C

D

1

6

5

2

43

7

+vcc

555 TIMER

IR transmitter uses 555 timer in

astable mode for the signal

enhancement .

COMPONENTS RATING:

RA -10K.

RB - 22K.

F - 38.5KHZ.

FORMULA USED:

F = 1.45

(RA + RB ) c

ASTABLE MODE:

Output

Input to LED


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IR RECEIVER

DESCRIPTION:

The TSOP17...-series are miniaturized receivers for infrared remotecontrol systems used for the same in the project. PIN diode and preamplifier areassembled on lead frame, the epoxy package is designed as IR filter. When IRreceiver1 receives the logic level 0, the P1.0 pin of ATMEL controller will beactivated. Correspondingly when received form IR receiver2 P1.1 pin will beactivated.

FEATURES: Internal filter for PCM frequency.

TTL and CMOS compatibility. Output active low. Low power consumption. High immunity against ambient light


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APPLICATION CIRCUIT

10Kohms

2

3

1 C

100ohms

10F

IR TXN.

TSOP 17..

VCC (+5v)
http://ex.pptx/http://ex.pptx/http://review-3%20ppt%289%29.pptx/http://review-3%20ppt%289%29.pptx/


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ENCODER (HT12E)

ENCODER OPERATION:

2^12 Series of

encoder begins 4-wordtransmission cycle uponreceipt of a transmissionenable(TE=0). Data istransmitted until TE=0. oncethe TE returns high theencoder output completes itsfinal cycle.

I\P pin for

address

OSC1, OSC2 RC Type R=10K

TE-Transmission enable

I\P pin

for

address

& data


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DECODER (HD12D)

DECODER OPERATION:

2^12 Series of decoder receives

data transmitted by an encoderthrough RF transceiver pair.

DECODER INTERPRETS:

a) The first N bits of code period as

address.

b) Last 12-N bits as data.HD12Dprovides 4 latch-type data

pins whose data remains unchanged

until new data is received.

Input add.

pins

output

data pins

OSC1,OSC2- RC type R=58 to 65K;C=0.1F

VT : Indicates valid transmission.


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RF TRANSMITTER MODULE-TX 01-ASK

GENERAL DESCRIPTION:

This TX 01-ASK Hybrid RFtransmitter module transmits theencoded data from HD12E typeencoder to the RF receiver through airat particular frequency of 433.92MHZ

FEATURES:

Frequency Range: 433.92 MHz

Supply Voltage: 3V to 6V

Output Power: 4 ~ 12 dbm

APPLICATION CIRCUIT


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RF RECEIVER MODULE-RX 02- ASK

APPLICATION CIRCUITGENERAL DESCRIPTION:

This RX02-ask Hybrid receiver

receives the particular RF Signal

of frequency (433.92MHZ)

through a single core antenna.

FEATURES:

Receiver Frequency: 433 MHz

Typical Sensitivity: 105 Dbm

IF Frequency: 1MHz

Low Power Consumption

Operating Voltage: 5V

MCU

VCC DATA


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POWER SUPPL Y CIRCUIT


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Reduction in inaccuracy in the transmission of data and overall cost can be

achieved.

The micro-controller used is a well-advanced version and also has the ability

to cope up with our software.

It can be implemented mainly in the rural areas where the existing design of

preventing the head-on collisions cannot serve its purpose.

This can be further implemented to have control room to regulate the working

of the system.

Thus the newly designed system to prevent accidents could overcome all

the demerits in the existing design and ultimately prove to be a better design as

the task of automation has been accomplished.

CONCLUSION

embedded based

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